1. Technical Field
The present invention relates to tanks, tank units, liquid ejection systems, and liquid ejection apparatuses.
2. Related Art
A known mode of a liquid ejection system or a liquid ejection apparatus is an inkjet printer (hereinafter also referred to simply as a “printer”) in which ink is discharged to printing paper to form an image. A printer usually includes an ink tank serving as a tank for containing ink to be supplied to a print head, which is a mode of a liquid ejection head, and a tank unit in which the ink tank is housed. The ink tank is provided with an air communicating path such that the outside air is introduced into the ink tank as the ink is consumed. Some kind of ink tank is provided with an ink injection port that enables a user to supply ink from the outside (e.g. see Chinese Patent Application Publication No. CN104015492A below).
Such an ink tank including the air communicating path and the ink injection port is attached to a printer, and is carried together with the printer with the ink contained therein, in some cases. When this printer is carried, for example, there are cases where the printer is brought into an orientation that is different from a usual orientation, which is assumed when the printer is used. There are also cases where the printer is disposed in an environment that is different from the usual environment, such as a place where the temperature is significantly higher than in an environment where the printer is used that is assumed at the time of shipping from the factory, or a place where the altitude is high and the atmospheric pressure is significantly low. For this reason, regarding this kind of ink tank, a device for preventing the ink in the ink tank from leaking from the air communicating path or the ink injection port even in such a situation is required.